Method of preparing moistureproof wrappings for perishable articles



' c. NICOLL 2,651,154 METHOD OF PREPARING M TU PR WRAPPINGS- FOR PERISHAE m Original Filed Jan. 1, 1946 Sept. 8, 1953 3 Z2, 1; &4

. ZZ Z g: T 51:5 J15 we I A YMM- prr-roaway Patented Sept. 8, 1953METHOD OF PREPARING MOISTUREPROOF WRAPPINGS FOR PERISHABLE ARTICLESCharles Nicoll, Gentilly, France Original application January 21, 1946,Serial No.

Divided and this application March 17, 1949, Serial No. 81,864. InFrance August Section 1, Public Law 690, August 8, 1946 Patent expiresAugust 4, 1964 and food products which may be adversely affected byatmospheric influences such as moisture in sheets of plastic material,such as for instance cellulose acetate which can be deformed by pressureor otherwise.

It is an object of this invention to provide means for protectingproducts which are likely, when stored, to deteriorate when they areexposed v to moist air.

In order to package such products, it has been proposed to coat thesheets of plastic material used as a wrapping with a moisture-proofvarnish.

However, if such varnish is applied to the inner side of the sheet, itis liable to impart to the 6 Claims. (01. 53-5) product an unpleasanttaste or to act on it in some other way. If on the contrary it isapplied on the outside, it is liable to become damaged in the course ofmanipulation and consequently not to retain its moisture-proofingefiect.

It has also been proposed to use composite sheets comprising anintermediate moisture-proof layer (latex, varnish or the like) enclosedbetween two sheets of plastic material. However,

. such composite sheets still possess certain disadvantages when theyare used for the packaging of products particularly sensitive tomoisture. If

v the wrapper is not applied closely to the product, it leaves aroundthe latter an atmosphere which may contain a high amount of moisture,which in the case of certain products may still increase and which mayhave a disintegrating action or other detrimental effect on the product.Moreover, wrappers made according to this method are in order to remedythese disadvantages, to manufacture moisture-proof wrappers fromcellulose acetate comprising recesses formed in accordance with the sizeand volume of the article to be packaged, and in which the wrappingswere constituted by two layers of cellulose .acetate between which wasinserted a layer of moistureproof varnish or the like. These compositesheets were then shaped by pressure to form therein recessescorresponding to the shape of the products to be packaged which requiredthe intermediate moistureeproof layer to possess the plastic qualitiesnecessary to permit the formation of such depressions without tearing,while retaining its moisture-proof qualities. However, owing tostretching, in the shaping operation, certain points of the sheetare'thinned down considerably and there is the risk of the intermediatewaterproof layer being torn and admitting moisture at these places.

It is an object of the present invention to avoid this by making itpossible to carry out the moisture-proofing of the wrapper subsequently,that is to say after the packaging of the product, and to permit the useof the waterproofing layer to be limited, in case of need, to thestrictly indispensable portions, and finally to permit the use of Vvarnishes which do not present the peculiar qualitles of elasticityheretofore required.

According to my invention, in order to obtain a waterproof wrapper fromsheets of cellulose acetate (or equivalent plastic materials) providedwith recesses intended to contain the products to be wrapped in one atleast of the components of the wrapper, two sheets of plastic materialare formed with such recesses and a layer of moisture-proof varnishrandadhering to the plastic material is applied between the two sheets andthe depressions of one sheet are then nested in those of the othersheet.

The uniting of the two sheets with the layer of moisture-proof varnishbetween them may be efiected before or after the articles to be packagedhave been placed in the cup-shaped depressions which are then closed bycementing to the combined sheets a covering also consistingof acombination of two sheets of plastic material with a moisture-proofvarnish between them, which may be flat or may be formed with similarcup-shaped depressions.

In the drawings affixed to this specification and forming part thereofseveral forms of packages produced in accordance with this invention areillustrated diagrammatically by way of example.

In thisdrawing- Figures 1 to 4 show various forms of wrapperswaterproofed conformably to my invention;

Figures 5 to 8 show other forms in which a clearance is left between thetwo sheets forming one of the two components of the wrapper;

Figure 9 shows still another form in which the waterproofing varnish isonly applied locally;

Figure 10 illustrates a package in which several plastic qualities asthesheets intended to form. the wrapper. Thereis thus a far greaterchoice of varnish available, since the latter need not be reallyplastic, but only slightly pliable. It will, in particular, be possibleto utilize varnishes the handling of which is very simple and offers nodanger, and comparatively cheap varnishes. The varnishes may be selectedamong the very transparent ones, there being no risk of theirtransparency deteriorating in the course of the operations of shaping ofthe depressions (under the influence of heat for instance), since thevarnish is applied only subsequently.

According to this invention, it is possible to arrange between the innerand the outer sheets a coating of varnish of any desired thickness. Itis also possibleto apply thevarnish with a spraygun, using suitablestencil-plates for the purpose of depositing a thicker coating on thebottom of the depression. It is even possible to deposit it in thedepressions and not on the plane portions, as shown in Figure 9.

To all these advantages are added those resulting from the interpositionof the moisture-proof coating between two sheets of plastic material:the absence of any influence of this coating on the packed productitself and the protection of said coating by the outer sheets of plasticmaterial, the varnish never being in contact with the tools or parts ofmachines utilized for the manufacture of the wrappers, during theclosing operations.

Wrappers according to the invention may comprise striated planeportions, lines of perforations for the separation of the individualpackages, tearing points for the opening of the individual cells, etc.in short, all the improvements applicable to wrappings of this nature.The new process may also be combined with the system in which anon-cemented zone is reserved around the base of the depression.

Modifications might of course be made in the details of embodiment ofthe above packings described as examples, without the general economy ofmy invention being thereby affected.

I claim:

1. The method of making a moistureproof package containing at least onearticle comprising the steps of molding a pair of inner sheets ofmoldable plastic wrapping material to provide in a first one of saidinner sheets at least one recess surrounded by plane portions, saidrecess being adapted to receive said article, and to provide in thesecond inner sheet a cover portion for said recess surrounded bycorresponding plane portions, molding a pair of outer sheets of similarmaterial with respective recess and cover portions conforming generallyto the contours of the recess and cover portions of said inner sheets;coating with a moistureproof varnish those surfaces of the conformingportions of one pair of said sheets which will be adjacent theconforming portions of the other pair; assembling said outer sheets injuxtaposition to the respective inner sheets with said layers ofmoistureproof varnish intervening, thereafter sealing at least parts ofsaid outer sheets to corresponding parts of said inner sheets; placingsaid article in said recess, and sealing the plane portions of saidinner sheets together to enclose said article.

2. The method of making a moistureproof package containing at least onearticle comprising the steps of molding a pair of inner sheets ofmoldable plastic wrapping material to provide inc. first one of saidinner sheets at least one recess surrounded by plane portions, saidrecess being adapted to receive said article, and to provide in thesecondinner sheet a cover portion for said recess surrounded bycorresponding plane portions, molding a pair of outer sheets of similarmaterial with respectiverecess and cover portions conforming generallyto the contours of' the recess and cover portions of said inner sheetscoating witha moistureproof varnish those surfaces of the conformingportions of one pair of said sheets which will be adjacent theconformingportions of the other pair; assembling said outer sheets injuxtaposition to the respectiveinner sheets with said layers ofmoistureproof varnish intervening, thereafter sealing at least parts ofsaid outer sheets to corresponding parts vof said inner sheets; andthereafter placing said article in said recess, and sealing the planeportions of said inner sheets together to enclose said article. 7 a

3. The method of making a moistureproof package containing at least onearticle comprising the steps of molding a, pair of inner sheets ofmoldableplastic wrapping material to provide in a first one of saidinner sheets at least one recess surrounded by plane portions, saidrecess being adapted toreceive said article, and to provide in thesecond inner sheet a cover portion for said recess surrounded bycorresponding plane portions, molding a pair of outer sheets of similarmaterial with respective recess and cover portions conforming generallyto the contours of the recess and cover portions of said inner sheets;placing said article in said recess, and sealing the plane portions ofsaid inner sheets together to enclose said article; thereafter coatingwith a moistureproof varnish those surfaces of the conforming portionsof one pair of said sheets which will be adjacent the conformingportions of the other pair; assembling said outer sheets injuxtaposition to the respective inner sheets with said layers of amoistureproof varnish intervening, thereafter sealing at least parts ofsaid outer sheets to corresponding parts of said inner sheets.

4. The method of making a moistureproof package containing at least onearticle comprising the steps of molding a pair of inner sheets ofmoldable plastic wrapping material to provide in a first one of saidinner sheets at least one recess surrounded by plane portions, saidrecess being adapted to receive said article, and to provide in thesecond inner sheet a cover portion for said recess surrounded bycorresponding plane. portions, molding a pair of outer sheets of simi--lar material with plane portions conforming gen-- erally to the planeportions of said inner sheets; and with respective recess and coverportions. deeper than the recess and cover portions of said innersheets; coating with a moistureproof varnish those surfaces of theconforming portions of one pair of said sheets which will be adjacentthe conforming portions of the other pair; assembling said outer sheetsin juxtaposition to the respective inner sheets with said layers ofmoistureproof varnish intervening, thereafter sealing at least parts ofsaid outer sheets to corresponding parts of said inner sheets; placingsaid article in the recess of said first sheet and sealing the planeportions of said inner sheets together to enclose said article.

5. The method of making a moistureproof package containing at least onearticle comprising the steps of molding a pair of inner sheets 7 ofmoldable plastic wrapping material to provide in a first one of saidinner sheets at least one recess surrounded by plane portions, saidrecess being adapted to receive said article, and to provide in thesecond inner sheet a cover portion for said recess surrounded bycorresponding plane portions, molding a pair of outer sheets of similarmaterial conforming closely to the contours of said inner sheets;coating with a moistureproof varnish those surfaces of the x'zoniformingportions of one pair of said sheets which will be adjacent theconforming portions of the other pair; assembling said outer sheets injuxtaposition to the respective inner sheets with said layers ofmoistureproof varnish intervening, thereafter sealing the plane portionsof said outer sheets to the corresponding plane portions of said innersheets; placing said article in said recess, and sealing the planeportions of said inner sheets together to enclose said article.

6. The method of making a moistureproof package containing a; pluralityof articles comprising the steps of molding a pair of inner sheets ofmoldable plastic wrapping material to provide in a first one of saidinner sheets a plurality of recesses surrounded by plane portions, eachsaid recess being adapted to receive one of said articles, and toprovide in the second inner sheet cover portions for said recessessurrounded by correspending plane portions, irloldin a pair of outersheets of similar material with respective recess and cover portionseach adapted to nesting'ly receive a plurality of the recess and coverportions or said inner s'lieets placing said articles iii Said artileieiyifi recesses of said one inner sheet and sealing the plane portionsof said inner sheets together to enclose said articles; thereaftercoating with a moistureproor varnish those surfaces of the opposedrecess and cover portions of one pair of said sheets Will be adjacentthe recess and cover portions of the other pair; assembling said outersheets in juxtaposition to the respetive inner sheets with said layersof moisturepifeof varnish intervening, and

thereafter sealing at least parts of said outer sheets to corres ondingparts of said inner sheets.

CHARL ES NiCOLLE.

